The wealthy are spending less money on luxury, and it might signal another recession. From penthouses to classic cars, here's what's just not selling in 2019.

In a December 2018 article for Forbes, market researcher Pamela N. Danziger wrote that the luxury retail market in 2019 should expect a hard year.

While the rich are getting richer and have more money to spend, she said, experiences are replacing luxury goods as a status symbol: "Where wealth used to be something the affluent wore proudly, today the wealthy are retreating into their cocoons, living behind walls and going increasingly inconspicuous."

It's part of the rise in discreet wealth, in which showing off wealth is no longer the preferred way to signify having money. Investing in education and health rather than luxury handbags and cars helps the rich gain — and maintain — access to what the middle class cannot.

Read more: A rise in discreet wealth is creating a new type of status symbol, and the elite are spending their money on 5 key lifestyle choices to keep up with it

In the US, the top 1% have been spending less on material goods since 2007, wrote Elizabeth Currid-Halkett in her book, "The Sum of Small Things: A Theory of an Aspirational Class," citing data from the US Consumer Expenditure Survey.

In 2019, several luxury fashion retailers and designers filed for bankruptcy, according to The Fashion Law; that includes Barneys New York, Sonia Rykiel, and Roberto Cavalli. Last year, iconic luxury brand Henri Bendel closed after 123 years in business.

Another segment of the luxury retail industry — jewelry — is on the decline, according to Richard Weisenfeld, president of the Jewelers Board of Trade (JBT), in a January 2019 interview with National Jeweler magazine. In 2018, 852 US jewelry retailers closed their stores, reported Laura Ewen for Retail Dive, citing JBT.

The jewelry industry is increasingly dependent on millennials, who just aren't as interested in diamonds as their parents were, reported Ray A. Smith for The Wall Street Journal. To appeal to this cohort, luxury brands like Bulgari are offering edgier jewelry lines at lower price points.

Consider iconic luxury jeweler Tiffany's — its sales have been suffering since 2016. Its 2018 holiday sales declined in both domestic and international markets, with a few exceptions to the latter, reported Danziger for Forbes.

In August 2019, Tiffany's announced it would be launching its first comprehensive jewelry collection for men in October to attract millennials and increase sales. The same month, the brand's shares increased by as much as 5%, reported Daniel Strauss for Markets Insider.

The first two quarters of 2019 saw art auction sales drop for the first time in years, reported Robert Frank for CNBC. Over the past year, Sotheby's sales and Christie's auction sales decreased by 10% and 22% respectively, he wrote.

According to Artsy, the art market has shrunk over the past decade when adjusting for inflation. A 2017 article by Artwork Archive reported that mid-market prices between $10,000 and $50,000 saw an increase in sales, while artworks over $1 million saw a decrease.

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Several art dealers told Rachel Corbett of Art Net last year that attendance is down in art galleries. Dealers expect gallery sales to continue to drop in the future more than any other sector, she wrote, citing TEFAF's 2017 market report. They expect deals to be more likely to occur at art fairs.

Wealthy people also appear to be spending less on art compared to other luxury items, Doug Woodham, managing partner of Art Fiduciary Advisors in New York, told Abby Schultz of Penta.

Spending on luxury cars may be booming, but spending is down when it comes to classic cars, Frank reported. Less than 50% of cars listed for $1 million sold at the Pebble Beach car auction — but those priced for less than $75,000 sold much more quickly, he wrote.

Classic car auctions in 2018 and 2019 saw a sell-through rate for cars priced at more than $1 million decrease by 20% compared to the year prior — the lowest since 2008, when Hagerty began tracking such statistics, reported Rob Sass for The New York Times.

The wealthy could be disinterested in the offerings or they could be feeling a change in the market, Brian Rabold, vice president for valuation at Hagerty, told Sass.

There are a few factors worth considering, according to Sass: Baby boomers are leaving the market and millennials aren't interested in buying or are priced out of the market, and there are general concerns about an economic downturn.